Page 30 - 2016Spring

William J. Murphy
Postal:
Division of Applied Research and Technology, Hearing Loss Prevention Team National Institute for Occupational Safety and Health 1090 Tusculum Ave., MS C-27 Cincinnati, OH 45226-1998 USA
Email:
wjm4@cdc.gov
Preventing Occupational Hearing Loss —
Time for a Paradigm Shift
Proactive hearing loss prevention programs that reduce workplace noise are shifting the focus from documentation of an injury to the prevention of occupational hearing loss.
Prevalence of Hearing Loss
In his classic text, de Morbis Artificum (Diseases of Workers), Ramazzini (1713) (Figure 1) identified copper smiths as workers exposed to hazardous noise:
“...at Venice, these workers are all congregated in one quarter and are en- gaged all day in hammering copper to make it ductile so that with it they may manufacture vessels of various kinds. From this quarter there rises such a terrible din that only these workers have shops and homes there; all oth- ers flee from that highly disagreeable locality. One may observe these men
Figure 1. Portrait of Bernardino Ramazzini (Wikimedia Commons, 2015).
as they sit on the ground, usually on small mats, bent double while all day long they beat the newly mined copper, first with wooden then with iron hammers till it is as ductile as required. To begin with, the ears are injured by that perpetual din, and in fact the whole head, inevitably, so that workers of this class become hard of hearing and, if they grow old at this work, completely deaf. For that incessant noise beating on the eardrum makes it lose its natural tonus; the air within the ear rever- berates against its sides, and this weakens and impairs all the apparatus of hearing. In fact the same thing happens to them as to those who dwell near the Nile in Egypt, for they are all deaf from the excessive up- roar of the falling water.”
Hearing loss in metalworkers is still common. Recordable hearing loss data from 2004 reported by the Bureau of Labor Statistics identifies workers in primary met- al manufacturing as having the greatest number of hearing loss cases per 1,000 workers compared to the other industries within manufacturing (Hager, 2006).
Hearing loss is an unseen illness that affects nearly 14 million workers in the Unit- ed States (Tak and Calvert, 2008). According to an analysis of the US National Health and Nutrition Examination Survey, an estimated 22 million workers are ex- posed to hazardous levels of noise, which put them at risk for occupational hearing loss (Tak et al., 2009). Tak and Calvert (2008) reported a prevalence of hearing loss in excess of 20% for workers in the railroad, mining, and primary metal manufac- turing industries. Among noise-exposed workers, Masterson et al. (2015) reported prevalence rates of 25% for the Mining and Construction sectors and 20% for the
28 | Acoustics Today | Spring 2016 | volume 12, issue 1 ©2016 Acoustical Society of America. All rights reserved.